Passengers in a bus look at a policeman aiming his weapon as he travels at the back of a police pickup truck with slabs of marijuana seized during an operation against drug dealers in Rocinha slum in Rio de Janeiro April 19, 2011. About 3 tons of marijuana were seized and seven people arrested during the operation, local media said. REUTERS/Ricardo Moraes (BRAZIL - Tags: CIVIL UNREST CRIME LAW SOCIETY)